Micro-Ct Analysis Of Process-Induced Defects In Composite Laminates Using Afp

Carbon fiber reinforced polymer (CFRP) composites have been gathering a lot of interest in several engineering applications because of their favorable properties including lightweight and ease of manufacturing. Robotic manufacturing techniques using automated fiber placement (AFP) for aerospace and automotive applications present a growing trend toward error-free manufacturing. AFP manufactured laminates can be prone to internal flaws due to improper selection of manufacturing process parameters. Additionally, internal damage in composite laminates can occur during the operational service of the laminate due to fatigue or foreign object impacts. Identifying and characterizing at the microscopic level may allow optimization of process parameters, leading to higher quality laminates. In this paper, a direct 3D imaging approach to characterize global and local deformation-induced defects in AFP manufactured CFRP laminates using X-ray CT techniques is presented. The investigations are conducted on two sets of thermoplastic PEEK composite laminates (undeformed and deformed) manufactured using a set of processing conditions. The presented approach to quantify the defects provides local and global statistics including the evolution of local 3D fiber orientation as a methodology to detect the degree of deformation.